<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <script>
      var num = prompt("请输入一个数字");
      if (num % 2 == 0) {
        alert(`${num}为偶数`);
      } else if (num % 2 == 1) {
        alert(`${num}为奇数`);
      } else {
        alert("请输入一个整数");
      }
    </script>
  </body>
</html>
